@@ -8,6 +8,7 @@
#define _NOLIBC_ARCH_AARCH64_H
#include "compiler.h"
+#include "crt.h"
/* Syscalls for AARCH64 :
* - registers are 64-bit
@@ -143,33 +144,16 @@
_arg1; \
})
-char **environ __attribute__((weak));
-const unsigned long *_auxv __attribute__((weak));
-
/* startup code */
void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) __no_stack_protector _start(void)
{
__asm__ volatile (
#ifdef _NOLIBC_STACKPROTECTOR
- "bl __stack_chk_init\n" /* initialize stack protector */
+ "bl __stack_chk_init\n" /* initialize stack protector */
#endif
- "ldr x0, [sp]\n" /* argc (x0) was in the stack */
- "add x1, sp, 8\n" /* argv (x1) = sp */
- "lsl x2, x0, 3\n" /* envp (x2) = 8*argc ... */
- "add x2, x2, 8\n" /* + 8 (skip null) */
- "add x2, x2, x1\n" /* + argv */
- "adrp x3, environ\n" /* x3 = &environ (high bits) */
- "str x2, [x3, #:lo12:environ]\n" /* store envp into environ */
- "mov x4, x2\n" /* search for auxv (follows NULL after last env) */
- "0:\n"
- "ldr x5, [x4], 8\n" /* x5 = *x4; x4 += 8 */
- "cbnz x5, 0b\n" /* and stop at NULL after last env */
- "adrp x3, _auxv\n" /* x3 = &_auxv (high bits) */
- "str x4, [x3, #:lo12:_auxv]\n" /* store x4 into _auxv */
- "and sp, x1, -16\n" /* sp must be 16-byte aligned in the callee */
- "bl main\n" /* main() returns the status code, we'll exit with it. */
- "mov x8, 93\n" /* NR_exit == 93 */
- "svc #0\n"
+ "mov x0, sp\n" /* save stack pointer to x0, as arg1 of _start_c */
+ "and sp, x0, -16\n" /* sp must be 16-byte aligned in the callee */
+ "bl _start_c\n" /* transfer to c runtime */
);
__builtin_unreachable();
}
move most of the _start operations to _start_c(). Signed-off-by: Zhangjin Wu <falcon@tinylab.org> --- tools/include/nolibc/arch-aarch64.h | 26 +++++--------------------- 1 file changed, 5 insertions(+), 21 deletions(-)